Apparatus for producing boards of filamentary material

ABSTRACT

A succession of rectangular mats, consisting essentially of asbestos fibers or other filamentary material held together by a wet hydraulic binder such as cement, are conveyed between two endless belts through the gap between a pair of horizontal platens of a press. At least the lower belt and platen are perforated to enable the application of suction to the underside of the mats whereby the same are held in fixed position on the lower belt at least on approaching the press and during compaction between the platens. The upper belt and platen may also have openings for facilitating the separation of the resulting board from the upper belt, upon the reopening of the press, by a blast of air under pressure.

United States Patent [11] 3,914,079 Kober Oct. 21, 1975 [54] APPARATUSFOR PRODUCING BOARDS OF 3,353,236 11/1967 Stedman 425/DIG. 201FILAMENTARY MATERIAL 3,737,276 6/1973 Hill et a1. 425/406 X 3,801,2434/1974 Smith et al 425/80 Inventor: Harald Kober, Wanne-Eickel,

Germany Primary Examiner-Robert L. Spicer, Jr. [73] Assignee: G.Siempelkamp & C0., Krefeld, n y, g Firm-Karl ROSS; Herbert Germany Dubno[22] Filed: July 23, 1973 57 ABSTRACT [21] Appl. No.: 381,435 1 Asuccession of rectangular mats, consisting essentially of asbestosfibers or other filamentary material [30] Forelgn Apphcatlon Pnomy Dataheld together by a wet hydraulic binder such as ce- July 29, 1972Germany 2237362 ment, are conveyed between two endless belts through thegap between a pair of horizontal platens of a press. I 425/ At least thelower belt and platen are perforated to en- 425/437; 425/DIG. 200 ablethe application of suction to the underside of the [51] Int. Cl. B29C3/04 mats whereby the same are held in fixed position on [58] Field ofSearch 264/109; 425/80, 81, 8,6, the lower belt at least on approachingthe press and 425/371, 225, 324 R, 406, 96, 411, DIG. during compactionbetween the platens. The upper 200, DIG. 201, 75, 437; /151 belt andplaten may also have openings for facilitating the separation of theresulting board from the upper [56] References Cited belt, upon thereopening of the press, by a blast of air UNITED STATES PATENTS underPressure- 2,457,784 12/1948 Slayter 425/80 X l 6 Claims 3 DrawingFigures 3,226,764 l/l966 l-Ioslettler 425/80 T0 HAT PRESS 021v:PRocmnm-R SUPPLIEE 1 l t 20 I I9 351.1- DRIVE US. Patent Oct.21, 1975Sheet10f2 3,914,079

Mum; JQQDW IIlllll HQ: DIN.

US. Patent Oct. 21, 1975 Sheet 2 of2 3,914,079

nmwmrnm X \IF III IV Av Al III/ /IV AV Av All All 11/ FIG. 2

2 /6 W COMPRESSED corzgessw All? APPARATUS FOR PRODUCING BOARDS OFFILAMENTARY MATERIAL FIELD OF THE INVENTION My present invention relatesto a method of and an apparatus for producing boards of filamentarymaterial, e.g., asbestos fibers, held together by a hydraulic bindersuch as cement applied in a wet state to a mat of such fibers.

BACKGROUND OF THE INVENTION Boards of this description can be seriallyproduced by forming a continuous web, consisting of the fibrous materialimpregnated by the wet binder, on the periphery of a rotating drum andcutting this web into usually rectangular sections consituting the matsthat are to be compacted in a press with relatively reciprocable lowerand upper platens. Conventional transporting mechanisms, designed toconvey these mats to the press, cannot handle them as fast as they comefrom the supply drum; this is true because the wet mats slide easily ona fast-moving conveyor and thus do not invariably remain thereon in aposition designed to align them with the press platens just prior totheir closure. It has therefore been the practice heretofore to assemblea number of such mats, with interposition of separating layers, in astack for joint compaction in the press. The stacking and subsequentunstacking of these mats requires additional equipment and/or manualwork; also, since the several mats of a stack at the instant of pressinghave been in existence for different lengths of time and have thereforereached different degrees of preliminary setting of their binder,production is not uniform.

' OBJECTS OF THE INVENTION The general object of my present invention isto provide a method of producing such boards without the need forinitial stacking, i.e., with individual pressing of each mat as soon asit arrives from the supply station.

A related object is to provide an apparatus for making such boards bysimple means and in a continuous operation.

SUMMARY OF THE INVENTION In accordance with my present invention, theoncoming mats are consecutively moved on a perforated conveyor through apressing station for compaction with expulsion of excess watertherefrom; the mats are held in position on the conveyor, on their wayto the press as well as within same, by suction continuously applied totheir undersides through the conveyor.

To facilitate the maintenance of the applied suction inside the press,the lower press platen has perforations communicating with suction meanssuch as the intake side ofa pump, the same or similar suction meanscommunicating with perforations of a support surface disposedsubstantially at the level of the lower platen on the entrance side ofthe press. If desired, such a perforated support surface subjected tosuction may also be provided again substantially at the level of thelower platen on the exit side of the press, both perforated surfacesbeing overlain by the upper run of the conveyor which passes between theperforated lower press platen and the confronting upper press platen. Ifdesired, either or both of these platens may be heated to accelerate thehardening of the binder; in any event, the water squeezed out from themat during the compaction step is drained off through the perforationsof the lower platen which thus have a dual function.

According to another advantageous feature of my invention, themat-carrying perforated conveyor is synchronized with an endless bandwhich passes, in its entirety or at least with its lower run, betweenthe two platens above that conveyor so that each mat is sandwichedbetween the conveyor and the band on traveling through the gap betweenthe platens. The band may also be perforated in order to be traversed bya blast of air or other fluid under pressure, exiting from one or morepassages in the upper platen upon the reopening of the press, whichserves to separate the compacted mat from the upper platen and from theband upon its discharge from the press. The continued application ofsuction to the underside of the mat as it exits from the press, via asecond perforated support surface as mentioned above, further aids inthis separation.

If the upper platen is vertically reciprocable, the band overlying theconveyor should be somewhat yieldable or guided with enough slack toallow for such reciprocation. The lower platen is preferably stationaryso as not to subject the matsto sudden level changes. If the press framecarrying these platens is fixedly positioned, the motion of the conveyorand of the overlying band may be temporarily halted at the instant ofpress closure; it is also possible, e.g., as disclosed in commonly ownedUS. Pat. No. 3,607,561, to mount this press frame on a horizontallymovable carriage and to let it travel with the upper conveyor run duringthe time of closure, the press returning to its starting positionimmediately thereafter in preparation for the compaction of the nextmat.

BRIEF DESCRIPTION OF THE DRAWING The above and other features of myinvention will now be described in detail with reference to theaccompanying drawing in which:

FIG. 1 is a side-elevational view, partly in section, of a pressingstation forming part of an apparatus for producing filamentary boards inaccordance with this invention:

FIG. 2 is a view similar to that of FIG. 1, but drawn to a larger scale,of the entrance side of the pressing station; and

FIG. 3 is a cross-sectional view taken on the line III- III of FIG. 1.

SPECIFIC DESCRIPTION The apparatus shown in the drawing comprises aconventional one-stage press with a frame 1, a vertically reciprocablebeam 2 carrying an upper platen 4, and a stationary beam 3 supporting alower platen 5. The beam 2 is coupled to a conventional drivingmechanism 18 controlled by a programmer 20 in the rhythm of anonillustrated supply station, such as the aforedescribed drum,delivering a succession of mats l2 essentially composed of asbestosfibers and cement. The mats are deposited on an endless conveyor belt 8in the form of a wire mesh, this belt being led around two rollers 23,24 with its upper run passing through the gap between platens 4 and 5.Roller 23 is shown coupled to a driving mechanism 19 which is alsocontrolled by the programmer 20. If necessary, the belt 8 may becomposed of a plurality of sections articulated to one another, themovement of the belt being so co-ordinated with the operating speed ofthe supply station that the mats l2 deposited on the belt do not come torest on the junctions between these segments.

Platen 5 is provided with a system of internal channels 6 opening at amultiplicity of locations at its top side overlain by the upper run ofthe perforated belt 8. These channels communicate, through a conduit 6,with a vacuum chamber in a hollow support 10 whose perforated uppersurface is level with that of platen 5; support 10 is rigid with beam 3and underlies the upper run of belt 8 upstream of thepress, i.e., on theside where the oncoming wet mats 12 enter the gap between platens 4 and5. A similar hollow support 17 on the downstream side, also rigid withbeam 3, underlies the upper belt run and forms a vacuum chambercommunicating via a pipe 6" with the channels 6 of platen 5. The twovacuum chambers and the channels 6 are maintained under low pressure bybeing connected to the intake side of a suction pump 21 .via a conduit22.

An endless band 9, whose construction may be similar to that of belt 8,passes with its two runs through the press gap immediately below theupper platen 4. The latter, as shown in FIG. 3, is provided withinternal passages 16 to which a blast of compressed air is delivered,under the control of programmer 20, upon every rise of beam 2 and platen4 after the compaction of a mat 12 between the two platens. The airblast passes through the perforations of band 9 and helps detach thecompressed mat from that band and from the upper platen.

The continuous operation of suction pump 21 insures that each mat 12remains in an invariable position relative to the upper run of belt 8,from the point of its delivery to the belt by the supply station to thepoint of its dischargefrom that belt on the exit side of the press.

To control the moisture content of each mat, especially on its top sidesubjected to more rapid evaporation, a sprinkler 14 continuouslyirrigates the band 9 on the entrance side of the press where this bandis led around rollers 13, one of them being shown driven by mechanism 19in synchronism with the band 8. At the exit side, where the band 9passes around guide rollers 23, a continuously rotating scrubbing brush15 cleans that band from adhering debris which are swept into an exhaust24.

It will be apparent that the single suction pump 21 may be replaced by aplurality of such pumps respectively connected to channels 6, vacuumchamber 10' and the corresponding chamber of support 17; the lattersupport could also be omitted in some instances.

The apparatus shown in the drawing can be operated at a conveyor speedwhich normally, in the absence of suction means 21 and perforatedsupport 10, would cause the mats 12 to slide onthe band 8 beforereaching the press platen 4.

If the apertures of the perforated conveyor 8 are large, a fine-meshwire screen or the like may be interposed between each mat and theconveyor, either as a continuous element or divided into individualsections,

as shown in commonly owned application Ser. No. 381,436 filed by mejointly with E. J. C. Huydts on even date herewith.

Compressed asbestos-cement boards produced with this apparatus can beused as substrates for making laminated plates of the type described inmy copending application Ser. No. 143,569 filed May 14, 1971, now,

patent No. 3,753,827.

I claim: 1. An apparatus for producing boards of filamentary material,comprising:

a press including a perforated lower platen and an upper platen spacedlyoverlying said lower platen,

said platens being vertically reciprocable relatively to each other;

a perforated endless conveyor having an upper run.

passing between said platens; support means for said conveyor providedwith a perforated surface substantially level with said lower platen atleast on an entrance side of the press underneath said upper run; and

suction means communicating with the perforations.

of said surface and of said lower platen for holding in position afilamentary mat, permeated by a wet.

hydraulic binder, deposited uponsaid conveyor outside the press forcompaction between said platens.

2. An apparatus as defined in claim 1 further comprising an endless bandhaving at least a lower run pass ing between said platens above saidconveyor, said band and said conveyor being coupled to each other forsynchronous motion with said mat sandwiched therebe- 4. An apparatus asdefined in claim 2,.further comprising irrigation means trained uponsaid band on said entrance side for controlling the moisture of the matbefore compaction.

5. An apparatus as. defined in claim 2, further comprising cleaningmeans for the mat-contacting surface of said band atan exit side of thepress.

6. An apparatus as defined in claim 1 wherein said support means hasanother perforated surface, commu-,

nicating withsaid suction means, disposed underneath said upper runsubstantially at the level of said lower platen on an exit side of thepress. l =l

1. An apparatus for producing boards of filamentary material, comprising: a press including a perforated lower platen and an upper platen spacedly overlying said lower platen, said platens being vertically reciprocable relatively to each other; a perforated endless conveyor having an upper run passing between said platens; support means for said conveyor provided with a perforated surface substantially level with said lower platen at least on an entrance side of the press underneath said upper run; and suction means communicating with the perforations of said surface and of said lower platen for holding in position a filamentary mat, permeated by a wet hydraulic binder, deposited upon said conveyor outside the press for compaction between sAid platens.
 2. An apparatus as defined in claim 1 further comprising an endless band having at least a lower run passing between said platens above said conveyor, said band and said conveyor being coupled to each other for synchronous motion with said mat sandwiched therebetween.
 3. An apparatus as defined in claim 2 wherein said band is perforated and said upper platen has a passage communicating with a source of fluid under pressure, said source being operable to separate the compacted mat from said upper platen upon withdrawal thereof from said lower platform.
 4. An apparatus as defined in claim 2, further comprising irrigation means trained upon said band on said entrance side for controlling the moisture of the mat before compaction.
 5. An apparatus as defined in claim 2, further comprising cleaning means for the mat-contacting surface of said band at an exit side of the press.
 6. An apparatus as defined in claim 1 wherein said support means has another perforated surface, communicating with said suction means, disposed underneath said upper run substantially at the level of said lower platen on an exit side of the press. 